TWO SAME TABLES, ONE UPDATED. HOW TO SYNC THE OTHER?
Hello
I have two tables -- A and B. The structure of both is the same. Only,
B has many indexes and is used for heavy duty SELECTs. On the other
hand, A only accepts heavy duty INSERTs, so has only one primary key
index.
So my DB design is such that A is only an INSERT table. Periodically,
say every 20 minutes or so, I would like to take all the new INSERTs
from table A and put them into B.
Is there any clever command to accomplish this? I'd rather not write a
PHP script with SQL to take every single new record, and update every
column of a new row in table B. For instance, can I do a replication
of only tables, not databases?
Thanks for any pointers!!
LB
--
Conan O' Brien gets it right!
http://blogs.pcworld.com/tipsandtweaks/archives/004369.html
On May 11, 11:06 pm, "L. Berger" <straightfwd...@gmail.com> wrote:
Hello
I havetwotables-- A and B. The structure of both is thesame. Only,
B has many indexes and is used for heavy duty SELECTs. On theother
hand, A only accepts heavy duty INSERTs, so has onlyoneprimary key
index.So my DB design is such that A is only an INSERT table. Periodically,
say every 20 minutes or so, I would like to take all the new INSERTs
from table A and put them into B.Is there any clever command to accomplish this? I'd rather not write a
PHP script with SQL to take every single new record, and update every
column of a new row in table B. For instance, can I do a replication
of onlytables, not databases?Thanks for any pointers!!
LB
Assuming ID is PK:
INSERT INTO b
SELECT *
FROM a
WHERE NOT EXISTS (
SELECT 1
FROM b
WHERE b.ID = a.ID
)
This query will run quite slow if tables are large, so - you may in addition
create a trigger-updated TIMESTAMP columns and search for changed data
through the recent created/updated elements only.
On 13 May 2007 02:21:30 -0700, rdeleonp@gmail.com <rdeleonp@gmail.com>
wrote:
Show quoted text
On May 11, 11:06 pm, "L. Berger" <straightfwd...@gmail.com> wrote:
Hello
I havetwotables-- A and B. The structure of both is thesame. Only,
B has many indexes and is used for heavy duty SELECTs. On theother
hand, A only accepts heavy duty INSERTs, so has onlyoneprimary key
index.So my DB design is such that A is only an INSERT table. Periodically,
say every 20 minutes or so, I would like to take all the new INSERTs
from table A and put them into B.Is there any clever command to accomplish this? I'd rather not write a
PHP script with SQL to take every single new record, and update every
column of a new row in table B. For instance, can I do a replication
of onlytables, not databases?Thanks for any pointers!!
LB
Assuming ID is PK:
INSERT INTO b
SELECT *
FROM a
WHERE NOT EXISTS (
SELECT 1
FROM b
WHERE b.ID = a.ID
)---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match